The other alteration to the 12-man group sees Scarlets winger Kristian Phillips make his first start since featuring in the last two legs of the 2012 campaign.

"Aled was injured in the last block but has progressed well during the year – he is a good addition to the squad," Williams told wru.co.uk ahead of the weekend.

"Lewis makes his debut at scrum half. He's been full of energy since coming in to the training set-up and it's good to introduce him to tournament play while we already know the threat Kristian poses out wide so it's exciting to involve him."